Correction

After publication of this work [1], we noted that we inadvertently failed to include the complete list of all coauthors.
The full list of authors has now been added and the Authors' contributions and Competing
interests section modified accordingly.

Competing interests

Dr Braun and Dr Sieper have held consultancies and received research honoraria, speaker's
honoraria and grants/research support from Centocor, Schering-Plough, Essex Pharma,
Wyeth and Abbott. Dr Zeidler has received speaker's honoraria from Essex Pharma. Dr
Burmester has held consultancies for Centocor, Essex Pharma, Wyeth and Abbott; has
received honoraria from Centocor, Essex Pharma, Wyeth and Abbott; has been a member
of a speaker's bureau for Centocor, Essex Pharma, Wyeth and Abbott; and has received
grants/research support from Centocor, Essex Pharma and Abbott. The other authors
declare no conflicts of interest.